federal law says you cant build one to sell it unless you have a FFL. as far as just building one for your use. it should be fine. im in NY not PA but i have built them no problem. its very easy and very fun to do. the stripped lower has to go through a FFL. but if PA is like NY. all the rest of it can be delivered to your door. unless there are local city, county laws restricting it.

__________________I have been a silent witness
to all of America's finest hours.
But my finest hour comes
when I am torn into strips and used as bandages
for my wounded comrades on the battlefield,
When I fly at half-mast to honor my soldiers,
Or when I lie in the trembling arms
of a grieving mother
at the graveside of her fallen son.

I know the lower have to go to ffl everything else I can have come to my house. And it is have me Do u think 5.56 or 223. I was told with 5.56 I can shot 5.56 and 223 but if I go with 223 I can just shot 223

I live in PA and have built a few, as long as they are for personal use and not for sale it is totally legal. I go with 5.56 because I never know when I'm going to come across cheap milsurplus and I enjoy the occasional tracer. Theres also the .223 wylde that some say can use 5.56 but I'm skeptical

Another question you might want to ask is what bore twist do you want?

I really dont I'm still looking in to it my friend told me he was goin to build one and he told me I should. So I still looking things up but I know I wanna go with 5.56 lower

check out the stickies at the top of the AR section. there is a lot of great info in them and should answer most of your questions.. and again, dont worry . its very easy to put together. if you can change a tire, or make toast. you can build a lower.

__________________I have been a silent witness
to all of America's finest hours.
But my finest hour comes
when I am torn into strips and used as bandages
for my wounded comrades on the battlefield,
When I fly at half-mast to honor my soldiers,
Or when I lie in the trembling arms
of a grieving mother
at the graveside of her fallen son.

I live in PA and have built a few, as long as they are for personal use and not for sale it is totally legal. I go with 5.56 because I never know when I'm going to come across cheap milsurplus and I enjoy the occasional tracer. Theres also the .223 wylde that some say can use 5.56 but I'm skeptical

Another question you might want to ask is what bore twist do you want?

Don't be skeptical and don't be dead.
If your rifle is only rated for .223, DO NOT USE 5.56

There are tons of websites to explain why.
Just don't do it.

Make sure your chamber and barrel are marked 5.56 and there will be no worries.

well if you are going for a precision type rifle, .223 may be better. But nowadays, hardly anyone makes .223 ar15s, most make Wylde chambers for precision uppers.

__________________Assumption is the mother of all ****ups.Know what you know, Know what you don't know. -Paul Pedzolt"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul